Troubleshooting & repair, Troubleshooting guide, Caution – Lincoln Electric SQUARE WAVE TIG 255 SVM100-A User Manual
Page 50
SQUARE WAVE TIG 255
F-9
TROUBLESHOOTING & REPAIR
TROUBLESHOOTING GUIDE
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
AC/DC Indicator on control panel
display show AC when polarity
switch is in the DC position, or vice
versa — machine has output but
balance control is not operable in
the AC TIG mode.
All red keypad LEDS are dark
but the control panel display is
operable. The machine has output.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
None
None
RECOMMENDED
COURSE OF ACTION
1.
Check leads #304 and #312 for
proper connections. Refer to
wiring diagram
2.
Check microswitch (S2A),
located on polarity switch (S2),
for proper operation.
3.
The protection/snubber board
may be faulty. See protection/
snubber board continuity test.
4.
Check control transformer (T2).
See control transformer voltage
test.
5.
If above checks are OK, then
replace the control board.
1.
The wiring harness between
the Control board and the LED
board may be faulty. Check for
defective plugs or loose wires.
2.
The Control board may be
faulty. Replace.
FUNCTION PROBLEMS
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric
Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.
CAUTION